During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee.

The river name is derived from the word leirr which means "clay".

The official blazon is "Or, a cross raguly vert" (Norwegian: I gull et grønt grenkors).

The arms were designed by Jarle E. Henriksen from the nearby town of Sandnessjøen.

The Sundøy Bridge connects the mainland to the northeastern part of the island of Alsta and the Helgeland Bridge connects it to the rest of Alsta and the town of Sandnessjøen.

The municipal council (Kommunestyre) of Leirfjord is made up of 19 representatives that are elected to four year terms.

The tables below show the current and historical composition of the council by political party.